Acid Blue 90

CI 42655; Coomassie brilliant blue G; brilliant blue G; C₄₇H₄₈N₃NaO₇S₂ = 854 (6104-58-1)

A dark brown powder with a violet sheen; some particles have a metallic lustre.

Complies with the following tests.

Light absorption A(1%, 1 cm) in a 0.001% w/v solution in phosphate buffer pH 7.0 at 577 nm, greater than 500, Appendix II B, calculated with reference to the dried substance.

Loss on drying When dried to constant weight at 100° to 105°, loses not more than 5.0% of its weight.